Having now looked at the weight of ahead converters, going ahead with a converter is only ever going to make things heavier, so this plan might not have legs.
It's currently about 15mm lower than pictured. I don't like totally slamming quill stems because when you remove them you have insert marks and scratches. Also, the more quill stem you have inside the steerer the more potential for sticking / jamming.
sorry, yes I mean steerer. Edited.
Having now looked at the weight of ahead converters, going ahead with a converter is only ever going to make things heavier, so this plan might not have legs.